mm_forum

I needed some userfields to be unique. So here is a solution where you can make any fe_users fields for mm_forum unique.

I decided to add a table column for other extensions which have to know that the field is unique. So they do not have to parse the TypoScript of the datarow.

I also found a bug: in the $updateArray and $insertArray of the edit/new function of the userfields in the backend module was a column 'meta'. But this column doesn't exist in the database. I commented it out, so that the sql statements are working again.

Please note: If it is very important for you that the userfields are unique be careful with other extensions and especially TYPO3 Backend. There is no check integrated if you haven't add one. At the moment mm_forum checks only in the registration and user profile if a userfield is unique. If there are more places where it should be checked -> please add the check.